The present invention relates to an apparatus and method of mounting and cooling electronic components, and more particularly to a modular heat exchanger and method in which removable modules carrying electronic components include a mounting plate and integral heat transfer ducts that conduct heat in uninterrupted thermal paths from the electronic components to the coolant in the ducts.
With reference to FIG. 1, a conventional heat exchanger 10 (shown in overhead plan view) may include a chassis 12 for plural mounting plates 14 carrying one or more electronic components 16. The mounting plates 14 may be placed in a thermally conductive relationship with the chassis 12 so that heat can be transferred from the mounting plates to a stream of coolant in contact with the chassis 12. Coolant passageways 18 convey the coolant past each of the plates 14 so that all of the plates may be cooled. The passageways 18 may have cooling fins (not shown) to facilitate heat transfer.
Various techniques are known for placing the mounting plates 14 in a thermally conductive relationship with the chassis 12. For example, a wedge clamp 22 may be placed in a recess 24 in the chassis next to an edge of a mounting plate and thereafter expanded so that the edge of the plate is pressed into contact with the chassis. In this and other mounting methods, however, the thermal path from the mounting plate to the coolant is interrupted. That is, the mounting plate 14 and the chassis 12 are separated by an interface 26. Microscopic air pockets may be trapped in the interface 26, reducing the efficiency of the heat transfer between the mounting plates and the chassis.
The efficiency of heat transfer in conventional heat exchangers may also be reduced by the alignment of the coolant passageways 18. When the passageways 18 are aligned generally perpendicular to the plates, such as depicted in FIG. 1, the coolant passes each of the plates. The temperature of the coolant flowing through the passageways 18 will gradually increase because the coolant sequentially draws heat from each of the plates 14, with the temperature difference between the interior of the passageway adjacent the last plate downstream and the coolant being smaller than the corresponding difference at the first plate upstream. As a result, less heat will be transferred from the last plates than from the first plates.
Conventional heat exchangers also may be heavier and waste more energy than in the present invention. For example, even though all of the slots for mounting plates in a chassis need not be filled, conventional heat exchangers are designed so that they are capable of handling the combined heat transfer requirements of the maximum number of plates which can be installed in the chassis. The number and size of the coolant passageways 18 and the number of fins 34 in the passageways are selected based on the maximum heat transfer capacity anticipated. When the electronic components generate less heat than capacity, the heat exchanger will be heavier than necessary by the weight of the unneeded passageways and fins. The additional weight is highly undesirable in an assembly that is to be used in airborne and other weight critical applications. Further, the heat exchanger will be consuming more energy than needed as the amount of coolant being pumped through the passageways will exceed the cooling needs of the exchanger, wasting energy used to pump the coolant and wasting coolant if it is vented overboard.
The present invention solves the above noted problems of the prior art heat exchangers. Each of the mounting plates of the present invention include their own integral heat transfer ducts (ducts being passageways of any cross-sectional shape and axial alignment with closed sides and open ends to contain and direct a fluid moving therethrough) so that the thermal paths from the plate to the interior surfaces of the ducts are uninterrupted, so that no unneeded ducting is carried when the heat exchanger is not operating at capacity, and so that the cooling capacity of the modules and heat exchanger may be tailored to match the specific heat transfer requirements of the electronic components on the mounting plate. Further, since each of the ducts conducts heat away from only a single mounting plate, coolant passes only one mounting plate before being exhausted.
Accordingly, it is an object of the present invention to provide a novel method and apparatus for mounting and cooling electronic components that obviates the problems of the prior art and includes removable modules with integral mounting plates and cooling ducts.
It is a further object of the present invention to provide a novel modular heat exchanger and method for mounting and cooling electronic components that improves heat exchanger efficiency by providing an uninterrupted thermal path from the electronic components to the coolant in the cooling duct.
It is yet a further object of the present invention to provide a novel modular heat exchanger and method for mounting and cooling electronic components that improves heat exchanger efficiency and reduces weight by providing each mounting plate with its own cooling duct.
It is still a further object of the present invention to provide a novel modular heat exchanger in which coolant in a duct flows past only a single mounting plate.
It is another object of the present invention to provide a novel modular heat exchanger and method for mounting and cooling electronic components in which heat exchanger capacity can be tailored to match the specific heat transfer requirements of the electronic components on the mounting plate.
These and many other objects and advantages of the present invention will be readily apparent to one skilled in the art to which the invention pertains from a perusal of the claims, the appended drawings, and the following detailed description of preferred embodiments.